Effects of Noncovalent Interactions on the Impact Sensitivity of HNS-Based Cocrystals: A DFT Study

We report the crystal packing, electronic structure, Hirshfeld surface, Bader’s atoms in molecules (AIM), and independent gradient model (IGM) for 2,2′,4,4′,6,6′-hexanitrostilbene (HNS) and HNS-based cocrystals (HNS/4,4′-bipyridine (BP), HNS/trans-1,2-bis­(4-pyridyl)­ethylene (BPE), and HNS/1,2-bis­(4-pyridyl)­ethane (BPA)) to understand how noncovalent interactions affect the impact sensitivity of the cocrystals. The results indicate that there are strong C–H···N interactions and π stacking in the three cocrystals. Among the three cocrystals, HNS/BP has the strongest intralayer hydrogen bonds and π–π interactions, which can be responsible for its lowest impact sensitivity. Among the emerging π–π interactions, the face to face interaction lying between components is the most important. Therefore, the strong intralayer hydrogen bonds and face to face π–π interactions determine the cocrystal explosives to have low impact sensitivity. Our work may provide useful information for understanding the safe performance of cocrystal explosives in atomic detail and broaden the application of supramolecular chemistry in the field of explosives.